Multifunctional composite

Abstract

A multi-functional, laminated composite comprises a plurality of cloth layers ( 3 ) penetrated by an infused matrix, wherein at least one cell ( 1 ) for energy storage is supported by and integrally built up from at least one of the cloth layers ( 3 ), the cell ( 1 ) being embedded in the matrix. The cell may comprise first and second electrodes ( 6,7 ) separated by a porous, separator layer ( 2 ) that has a liquid electrolyte-permeable, matrix-free intra-electrode region to which the electrolyte ( 2′ ) may be added before or after resin infusion to activate the cell. The structural composite may have integrated energy storage comprising a lithium-ion rechargeable cell, optionally of printed construction.

The invention claimed is: 
     
       1. A multi-functional composite comprising a plurality of cloth layers and a penetrating matrix material and having at least one cell for energy storage incorporated therein, wherein the cell is integrally deposited upon at least one of the cloth layers and comprises first and second electrodes separated by a porous, separator layer that has a liquid electrolyte-permeable, matrix-free intra-electrode region. 
     
     
       2. A multi-functional composite as claimed in  claim 1 , wherein liquid electrolyte is disposed within the liquid electrolyte-permeable, matrix-free intra-electrode region of the porous, separator layer. 
     
     
       3. A multi-functional composite as claimed in  claim 1 , wherein the composite comprises a supply network for supplying liquid electrolyte to the intra-electrode region. 
     
     
       4. A multi-functional composite as claimed in  claim 1 , wherein the at least one cell is integrally built up from only one cloth layer. 
     
     
       5. A multi-functional composite as claimed in  claim 1 , wherein the cell comprises a pair of half cells, each of which is integrally built up upon a cloth layer, and the half cells have been brought together to form a cell. 
     
     
       6. A multi-functional composite as claimed in  claim 1 , wherein the composite comprises two or more such cells that share a common separator layer extending between them. 
     
     
       7. A multi-functional composite as claimed in  claim 1 , wherein in the cell, all the respective electrode components are laid down by being integrally deposited as thin layers upon the cloth layer or upon other thin layers. 
     
     
       8. A multi-functional composite as claimed in  claim 1 , comprising a plurality of matrix material infused cloth layers overlaying one another and additionally held together by inter-laminar reinforcement. 
     
     
       9. A multi-functional composite as claimed in  claim 1 , wherein the cloth layers are either uniformly conductive across their area, or, are provided with conductive regions corresponding to the active cell areas, so that in either case they function as current collectors. 
     
     
       10. A multi-functional composite as claimed in  claim 1 , wherein one or more non-cell-bearing cloth or other dielectric layers is laid up adjacent a cellbearing cloth layer to prevent cross circuits. 
     
     
       11. A multi-functional composite as claimed in  claim 1 , wherein the composite is a continuous fibre reinforced composite, where the reinforcing fibres are glass or carbon fibres. 
     
     
       12. A multi-functional composite as claimed in  claim 1 , wherein the composite is in the form of a flat or curved panel. 
     
     
       13. A multi-functional composite as claimed in  claim 1 , wherein each cell is a battery or supercapacitor. 
     
     
       14. A method of preparing a multi-functional composite as claimed in  claim 1  having at least one cell for energy storage incorporated in the matrix, comprising the steps of:—
 i) assembling a plurality of cloth layers, wherein the at least one cell is integrally built up from at least one of the cloth layers, each cell comprising first and second electrodes separated by a porous, separator layer that has a liquid electrolyte-permeable intra-electrode region for receiving liquid electrolyte; and, 
 ii) infusing a matrix material into the cloth layer including the at least one cloth layer to form a matrix that penetrate the cloth layers but not the intra-electrode regions and hardens to form the composite. 
 
     
     
       15. A method as claimed in  claim 14  and further comprising the step of:
 iii) introducing a liquid electrolyte into the intra-electrode regions, wherein the electrolyte filling step occurs before, during or after the matrix infusion step. 
 
     
     
       16. A method as claimed in  claim 14 , wherein in step i) each cell is initially formed as a pair of half cells, each of which is integrally built up upon a cloth layer, prior to combining the half cells. 
     
     
       17. A method as claimed in  claim 15 , wherein the electrolyte introduction step iii) is conducted prior to matrix infusion step ii) by introducing the liquid electrolyte directly onto the porous separator while the cell is being laid up. 
     
     
       18. A method as claimed in  claim 15 , wherein the electrolyte introduction step iii) is conducted after matrix infusion step ii) via a supply network through which the liquid electrolyte is introduced into the intra-electrode regions. 
     
     
       19. A method as claimed in  claim 18 , wherein step i) includes the laying down of a network of capillary tubes leading to the respective intra-electrode regions. 
     
     
       20. A method as claimed in  claim 14 , wherein step i) further includes adding inter-laminar reinforcement to secure the cloth layers together prior to matrix-infusion step ii).